Point 1 is irrelevant: Every piece of music used in the VN is Royalty free or free to use non-commercially and every piece of music is credited in game.
All of the tracks ''''''taken'''''' from Echo like Court and Page are royalty free and can be used by anyone at any time by anyone for any purpose - if you who know how to access the YouTube Music Library, you can use it. It quite frankly doesn't matter what the Echo Project thinks - they don't own the rights to that music, the music was not made for Echo, it is theirs as much as mine or anyone else's.
Point 2: Well, I am no professional writer: so expect some scenes to feel a little weird - several scenes during ch1 will be updated next build.
You aren't supposed to know fully what is going on, that would - as lampshaded in game - spoil the story right at the beginning. The scene with Chase in the Hospital was also supposed to come off as confusing and Surreal as Eric is not fully acting as a fully functioning person during those scenes - And Chase is well, he has his own deal.
The thing with Character introductions is also something I can't really help, lots of people needed to be introduced for plot threads etc - and that won't be getting much better next build. I suppose this could've been addressed by breaking ch1 into 2 days but that was not in the plan.
Point 3: As I said before - lots of lore was left vague early as to not spoil the story - this is a mystery VN, there will be things that don't make sense at first.
I also am not really sure your point here, the first scene sets the tone for the overarching narrative, then you receive hints about the two major forces (Reps and the Memory Outbreak) at play in the game's world as early as the literal next scene before then formally being introduced to them both not even two scenes into chapter 1 alongside a necessary lore dump, ending off with the introduction of the three ''''''Main''''' characters, I don't think I could get any more concise than that other than improving the writing itself.
I rambled on a bit there, sorry.